The present invention relates to an adjustable anchorage for seat belts for the protection of vehicle occupants. The present invention finds application in what is known as a three-point seat belt system in which the seat belt and in particular the shoulder belt portion is looped through a D-ring or similar device which is often fixedly attached to the "B" pillar of a vehicle. The rigid attachment of the D-ring or anchorage to the vehicle does not provide flexibility in the operation of the seat belt system to accommodate varying sizes of the occupants. In a system employing a fixed anchorage, the anchor point is chosen to accommodate an occupant of average size. In this manner the shoulder belt is designed to contact the shoulder of the occupant and then extend diagonally across the occupant's torso to a buckle. This, however, is not the case with occupants who are taller or shorter than average. To accommodate for varying size of occupants, adjustable anchorage mechanisms have been proposed in the prior art, one of which is the commonly owned U.S. Pat. No. 32,524. Other adjustable anchorage mechanisms can be found in U.S. Pat. No. 4,556,255 as well as in a variety of Great British patent applications such as 2,124,889; 2,132,071; 2,136,070 and 2,138,670.
It is an object of the present invention to provide a manually adjustable seat belt anchorage which is of simple construction and one which maintains its structural integrity and performance during high deceleration and vehicle crash situations.
Accordingly, the invention comprises: an adjustable seat belt anchorage comprising: a guide rail adapted to be secured to a portion of a vehicle generally at or above occupant shoulder height. The guide rail forms an an open channel, and includes a plurality of pairs of cut-outs oppositely positioned in a front walls of the guide rail. The anchorage further includes a latch plate assembly comprising: a resilient carrier slidingly received within the channel; a latching mechanism is biased into the guide rail by the carrier and supported by and movable within the carrier. The latching mechanism includes a latch bar extending upwardly from the carrier for engaging a selected pair of cut-outs and an attachment means such as a threaded bushing for supporting a safety belt support device such as a D-ring. The support or D-ring is adapted to receive a portion of the safety belt, wherein the point of attachment of the D-ring is located relative to the latch bar means in a manner that forces and torques exerted upon the safety belt and D-ring tend to urge the latch bars into the cut-outs in the guide rail. A spring is provided to bias the latching means upwardly. The spring includes a coiled portion slidably received within a portion of the carrier and extendable along the guide rail as the carrier is moved therealong including an attachment end secured to the guide rail proximate a mechanical first stop.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.